Furnace structure



June 17, 1930. .1. w. GATES FURNACE STRUCTURE Filed Sept. 10, 19 5 2 Sheets-Sheet 1 June 17, 1930. J, w, GATES 1 1,763,925

FURNACE STRUCTURE Filed Sept. 10, 1925 2 Sheets-Sheet 2 HIHHIH lli lu W Jfon W 64564 I I m 22 i @5 $15 {Ii him? M Patented June 17, 1930- UNITED STATES PATENT; OFFICE JOHN W. GATES, OF MONTREAL, QUEBEC, CANADA, ASSIGNOR, BY MESNE ASSIGNMENTS, AIIlIIIILRICAN AIR-COOLED BLOCK-ARCH COMBUSTION CO. INC., OF NEW YORK, N. Y.,

A CORPORATION OF NEW YORK .t FURNACE STRUCTURE Application filed September-10, 1%125. Serial No. 55,469.

This invention relates to furnace structures, and more particularly to a wall structure for furnaces embodying means for supplying air preheated by the products of combustion to spaced zones in a combustion chamber for the purpose of supplying additional oxygen to the unignited gas and thereby augmenting the flame mass which impinges upon the water tubes or other heat absorbing elements of the furnace. In ad-.

-dition, my present invention provides means for supplying atmospheric air in substantial volume and causing the same to traverse substantially the entire inner surface area of the wall so that the rapid burning out of the wall structure and frequent replacemen thereof is obviated.

It is another object of the invention to .provide a construction which is particularly adaptable for use in the roof or arch wall of a furnace and wherein I provide the main arch wall with a subjacent Wall in parallel relation thereto and detachably suspended therefrom. The space between these walls provides an air receiving chamber, said chamber being open at the front and rear ends of the arch Wall so that the air is drawn by induction,..caused by the natural draft through the furnace, fromsaid chamber into the furnace combustion chamber at its front and rear ends. I

It is another object of the invention to provide a furnace wall structure composed of individual blocks of refractory material arranged in rows and separate hanger elements each having means from which a plurality of the block rows are suspended whereby any one of the hanger elements with the series of rows of the wall blocks .suspended therefrom may be removed from This application is input a continuation of a prior application for atent filed by me on September 13, 1923, erial No. 663,163.

With the above and other objects in view, the invention consists in the improved furnace wall'structure and in the form, construction and relative arrangement of its several parts as will be hereinafter more fully described, illustrated in the "accompanying drawings, and subsequently incorporated in the subjoined claims.

In the drawings, wherein I have illus trated, one practical and satisfactory embodiment of the invention and in which similar reference characters designate corresponding parts throughout the several v1ews,

Figure 1 is a vertical, longitudinal section through a part of the furnace showing the same provided with an arch wall embodying my presentdmprovements, said section being taken substantially on the line l1 of.

Fig. 2;.

Fig. 2 is a fragmentary top plan view of the arch wall, parts of the harness and the main wall blocks being omitted tov show the subjacent Wall structure;

Fig. 3 is an enlarged transverse sectional View taken substantially on the lines 33 of Figs. 1 and 2;

Fig. 4 is a fragmentary front. elevation, a part of the front wall of the furnace being omitted;

Fig. 5 is a detail perspective view of one of the main wall blocks;

Fig. 6 is a similar view of one of the hanger blocks of the subjacent wall;

Figs. 7 and 8 are detail perspective views responding to that shown in Fig. 7 showing the same in inverted positionrelative thereto as occupied in the subjacent wall structure.

In the embodiment of the invention which I have selected for purposes of illustration, I'have shown the essential features thereof incorporated in the roof or arch wall of the furnace combustion chamber, though it will be apparent as the description proceeds that of other blocksof the subjacent wall, and

Fig. 9 is a perspective view, the block cor-,

certain of these novel features might in some instances, be advantageously employed in the structure of the side walls of the furnace. For the purpose of supporting this arch wall structure in position, I provide a plurality of harness elements 5, which asherein shown are in the-form of tubes arranged in spaced parallel relation to each other extending transversely of the furnace and having their of the drawings.

in thickness so that .structure.

opposite open ends suitably mounted in the side walls thereof. To each of these hanger elements 5 a plurality ofrelatively short tubes 6 arranged in spaced'relation to each other and extending longitudinally 'of the furnace are connected b means of suitable couplings 7 whereby an may freely pass from the tubes 5 intosaid tubes 6, the latter tubes being closed at their opposite ends.

The main arch wall of the furnace is composed of' a multiplicity of blocks 8 of fire clay or other suitable refractory material, one of which is illustrated in detail in Fig. 5

In the illustrated construction, three transversely extending rows of these wall blocks are connected with the tubes 6 of each of the harness elements 5 and supported in suspended relation therei from. For the purpose of receiving the tubes 6 the opposite-side faces of each block at its upper end are recessed as at 9 whereby the upper portions of the blocks are reduced upwardly between the adjacent tubes 6, the side faces of said reduced upper end portions of the blocks being beveled'or inclined for blocks from the supporting harness since such subject matter is fully disclosed and claimed in Patent No. 1,404,845 issued to me I on January 31, 192

Each of the blocks 5 is further provided in its opposite side faces below the recesses 9 with vertically extending channels 11 which are flared or gradually increased in width from a point intermediate of their ends to the lower face of the block. The mating channels of the adjacent wall blocks provide vertically extending air passages to the upper ends of which airis supplied from the tubes 6 through thespaced openings 12 in the walls of said tubes-at the lower sides thereof. However, I 1 do not claim herein the specific means for supplying atmospheric air through the furnace arch wall,s1'nce such means likewise .is fully described and claimed in a second Patent No; 1,500,123 issued to me on July8, 1924=.

From the foregoing descriptlon, at will be jnally of the furnace structure.

they may be inserted.

observed that unlike the harness structure for supporting the wall blocks as shown in .my issued patentfirst above referred to, I

provide separate main harness elements unconnected with each other' and suspend from the spaced shorttubes' 6 of each of these harness elements a plurality of rows of the wall blocks. Thus it is possible to assemble the block rows with the individual harness elements before the latter are erected in position in the furnace structure, thus en abling the work of erection to be greatly expedited. Likewise, it'is possible, when necessary, harnesselements with the series of rows of to. remove any one oftheseparate wall blocks suspended therefrom without I disturbing the other harness elements or. the remaining rows of wall blocks connected therewith, It will be apparent that though I have above described and in the drawings illustrated the harness tubes 5 as being transversely positioned and the short tubes 6 extending longitudinally of the furnace, such relative arrangement of the tubes 5. and 6- I might be reversed if desired, so thateach of the harness elements would thensupport a series of block rows extending iongitudi- In subjacent spaced relation to the main arch wall, a second wall is arrangedand is .likewise composed of a plurality of rows.

of blocks which, however, are relatively thin and formed of material of high heat conductivity, such as carborundum. While this subjacent wall in so far as 'thebroader aspects of my present improvements are concerned, might well be constructed in the form of one continuouslslab or structure, I find it convenient to use individual blocks of relatively small dimensions which may be readily arranged .relative to each other to provide an wherein the individual blocks are capable of independent removal or replacement. This subjacent wall structure and. the means which I provide for detachably suspending the same from the main arch wall composed of the blocks 8 in one practical embodiment {hereof may be described in detailvas folows:

Eachof the arch blocks 8 has a transimperforate wall structure versely extending recess 13 in one of its side a I faces. The upper portion of each recess 13' v has a cylindrical or curved surface and in certain of the blocks'at the lower side of said curved surface the transversely extending shoulder 14 is formed at ,the upper" endof the vertical plane surface 15 of the lower v arch wall the recessed side faces are not. provided with the shoulders 14 but the vertical plane surface of said recess, extendsat portion of the recess. In other blocks of the a tangent from the cylindrically curved sur-- face of the upper portion of'the recess. The

rows ofblocks are assembled with the having the recesses as shown in" Fig. ar-" ranged in one row with the recesses of adjacent blocks mating as shown in Fig. 1, while in the adjacent row of blocks extending longitudinally of the wall the recessed faces of the adjacent blocks which align with the recesses of the first row of blocks are of the construction lastdescribed and not provided with the shoulders 14. Thus, it will be understood that in the latter row of blocks the lower entrance ends of said recesses are equal to the maximum width of the upper portions of the recesses whereas in the other block rows, the plane faces 15 of-the recesses are closer to each other, thus narrowing the entrances to the recesses in the latter blocks.

The subjacent wall includes hanger blocks 16 preferably of rectangular form, and each gular form and terminating in a cylindrical enlargement 19. This enlargement is of such diameter that it may be inserted upwardly into the mating recesses of the blocks 8 which are not provided with the shoulders 14. The hanger block is then shifted longitudinally through the latter recesses and into the curved or cylindrically. formed upper ends of the recesses in the blocks of the adjacent row. The cylindrical end 14 of the lug 18 on the hanger block being of greater diameter than the distance between the plane Vertical surfaces 15 of the recesses inthe latter arch blocks, said hanger block is thus suspended in position beneath the arch blocks and with the cylindrical enlargement 19 resting upon the shoulders 14. In this manner, it will be seen that the hanger blocks may be easily and. quickly attached to the main arch wall in equi-distance spaced relation to eachother and with the longer dimensions of said blocks extending trans versely of said wall. However, while I have so illustrated the device in the accompanying drawings, it will be understood that if desired the recesses of the arch blocks may extend longitudinally of .the wall without changing the structure in other particulars or requiring a different method of assemblage of the subjacent wall blocks from that which will be presently described. v

The subjacent wall also includes additional blocks 20 and 21 respectively, which are illustrated in detail in Figs. 7 and 8 of the drawings. Each of the blocks 20 at one side thereof has its longitudinal edges rabbeted to provide the flanges 22 thereon while at the opposite side of the block the end edges thereof are rabbeted to provide the flanges 28. Thus, it will be understood that the flanges 22 and 23 of the blocks 20 are disposed in different planes. The blocks 21 have their side and endedges rabbeted on marginal flanges'24 similar to the hangerblocks 16. As shown in Fig. 2 of the drawings, after the hanger blocks have been 5115- pended from the arch wall as above described, in the spaces between the hanger blocks in each longitudinal row the blocks 20, disposed in the position seen'in Fig. 7 of the drawings, are arranged with the longer dimension of said block extending transversely of the wall so that the side,

flanges 22 thereof overlap and rest upon the side flanges of the hanger blocks 16 formed by the longitudinal rabbets 17. The end flanges 22 of the blocks 20 will thus be pos'i-- 0 tioned in the same plane as the lower portions of the hanger blocks. Additional blocks 20 in the inverted position shown in Fig. 9 are then arranged in position between the transversely spacedhanger blocks with end flanges of the hanger blocks. Finally the additional blocks shown in Fig. 8 are arranged in position between" the longitudinally and transversely spaced blocks 20' 1 and with the flanges 24 thereof engaged upon the end and side flanges respectively of the latter blocks. In inserting the last named blocks in place, they are passed upwardly between the adjacent blocks already in position'at an oblique angle and then turned to a position parallel with the wall structure and lowered iintil the flanges 24 properly seat on the flanges of the previously assembled blocks. In this manner, it will be seen that by means of the individual blocks or units an imperforate wall structure may be produced and that the majority of the blocks constituting the subjacent wall structure have no direct physical connection'with the arch wall proper, so that the removal of any one or more of said blocks when necessary and their replacement by new'blocks can be quickly effected. Also by simply re moving certain of the blocks 20 from the .the end flanges 23 thereof resting upon the wall is thus assembled and suspended, from the main arch wall it is disposed in spaced parallel relation to the latter wall, thereby providing an air receiving chamber 25 which extends substantially over the entire inner surface area of the arch wall. Fur;

ther, it will be observed from reference to" within the combustion chamber of the fur-- nace. Preferably, though not necessarily, the opposite side edges of the subjacent wall are in abutting contact-against the side walls of the furnace as shown in Fig. 4 of the -furnace, the natural At the rear end of said subjacent wall however, there is free communication between chamber and a secondary combustion zone B within the furnace combustion chamber. Thus it will be underdrawings.

stood that during the operation of the draft throughthe com ducting capacity, such air becomes highly.

heated. Due to the high pressure in the front end of the furnace combustion chamher and the line of draft flow of the proddrawn into the combustion-zones A and B acts of, combustion rearwardly therefrom to the outlet flue, there is a tendency to create a partial vacuum inthe upper forward end of the combustion chamber and in the forward end portion of the chamber 25 so .that a part ofthe preheated air will be drawn from this chamber into the combust1on zone A." This preheated air being suppliesadditional oxygen to the uni nited fuel so that complete combustion of a 1 fuel will be obtained and the mass of flame passing upwardly from the combustion chamber at the rear end thereof into contact with the water tubes and other heat absorbing ele-. ments appreciably augmented.

Another advantageous feature of the structure above described resides in the fact that by reason of the continuous induced I supply of cool atmospheric air entering the rhamber 25 through the recesses or passages 11 in the, arch wall structure and the free circulation of this airover the entirefinner face of the arch wall, the intense heat from the combustion chamber of the furnace isto a large extent absorbed and the rapid deterioration or burning out of'the blocks of the arch wall structure is prevented. By constructing the subja'cent Wall forming the lower side of the chamber 25 and suspending the same fromthe arch wall in the manner above described, a more or less confined stream or sheet of relatively cool air is being constantly circulated in contact with the inner face of the arch wall. The blocks of the subjacent wall being'relatively thin and of comparatively light weight, the arch -wall structure and its supporting harness are not subjected to great strain nor is there any possibility that'the suspending lugs or projections on the hanger blocks may break and permit the subjacent wall to fall into the combustion chamber. Also, it will be observed that the construction and manner of suspending the subjacent wall permits of the relative expansion and contraction of the different elements thereof which may occur owing to variations in temperature at -the opposite sides of the wall structure. The provision of this subjacent wall effectively baflies the flame and prevents direct contact thereof with the refractory mate rial of the arch wall, thus providing an effective protection for the latter. The relatively light blocks or units comprising said subj'acent wall can be quickly removed when burnt out and replaced by new blocks so that the time during which the furnace must be shut down for repairs will be a fraction of that which would be required to remove and replace the blocks or units of the mainarch structure.

From the foregoing description, the construction and several novel features of my present invention will be fully understood. The improvements herein described are applicable to various different types of furnaces, and by reason of the fact that the furnace wall is not only protected against rapid deterioration,v from the intense heat,

but also that the maximum heating efficiency from the fuel consumed will be obtained,

the furnace may beoperated very economically. Also, it is apparent that thecost of maintenance of a furnace provided with my present invention will be materially vless than that incident to furnaces of the construction now in general use.

I have herein shown and described an embodiment of my present improvements which has given highly satisfactory results" in practice. Nevertheless, it is to be under stood that in so far as the-essentials thereof are concerned, the several structural part-s might be produced in various other alternative forms. Accordingly, it is to be understood that I reserve the privilege of resorting to all .such legitimate changes in the form, construction and relative arrangement of the detail parts as may be fairly embodied within the spirit and scope of the invention as claimed.

I claim:

1. In a-furnace structure, an arch wall comprising a plurality of rows of blocks having portions forming parallel channels in the inner faceof the wall, each channel at spaced -'intervals having restricted entrance portions, and a .protecting wall for i said arch wall extending in. spaced parallel relation to the inner face of said arch wall and consisting of a plurality of hanger in the inner face of the wall, each channel at spaced intervals having restricted entrance portions, and a protecting wall for said arch wall extending in spaced parallel relation to the inner face of said arch wall and consisting 'of a plurality of hanger blocks having means insertable through the unrestricted portions of said channels and movable into the restricted portions thereof to sustain said blocks in suspended relation to the arch wall, additional blocks disposed between and supported by said hanger blocks, and a third series of blocks positioned between and supported by said second named blocks. I

3. In a furnace structure, an arch wall comprising a plurality of rows of blocks having portions forming parallel channels in the inner face of said wall, each of said channels at spaced intervals being of less width at the bottom than at the top, and a protecting wall for said arch wall disposed in spaced parallel relation to the inner face thereof and embodying wall blocks each provided with a tongue insertable through one of the unrestricted portions of the channel andadapted for movement into a restricted portion of the channel whereby said wall blocks .are suspended from'the arch wall for independent detachment therefrom.

4:.111 a furnace structure, an arch wall comprising a plurality of rows of blocks having portions forming a lurality of parallel channels in the inner ace of the wall, each of the channels at. spaced intervals having restricted entrance portions, and a protecting wall for the arch wall disposed in parallel, relation to the inner face thereof and embodying a plurality of hanger blocks having tongues enlarged at their ends and adapted to be inserted through the unrestricted portions of the channels and moved into the restricted portions thereof whereby said hanger blocks are suspended from the arch wall for independent removal therefrom, and additional blocks disposed between and spacing the hanger blocks from each other to prevent movement of said tongues into the unrestricted portions of said channels.

- 5. A furnace arch wall structure embodying a plurality of rows of refractor blocks and a facing wall suspended from said structure in spaced relation thereto and including members arranged in rows, the members in each row being spaced apart, and each of said members having means for cooperative engagement with means on certain of said re ractory blocks to suspend said members for attachment to or detachment from said blocks independently of each other, and means for remov'ably locking the spaced members in each row in such suspendedre lation to said blocks against relative movement.

6. A furnace arch embodying an upper or backing course having channels in the lower surface thereof, the said channels being in places of less width at the bottom than at the top, and a lower or facing course including tongues enlarged at their upper ends and adapted for insertion in the unre-' stricted portions of said channels and for movement along their recesses into the restricted portions thereof, whereby the lower course will be suspended from the upper course and may be removed therefrom.-

7 A refractory structure embodying a row of backing blocks and a row of facing blocks, tongues on certain of said facing blocks having interlocking engagement with the backing blocks, the remaining facing blocks serving to hold the tongues in interlocking en gagement with the backing blocks and being individually removable topermit release of the interlocking engagement between any adjoining tonguedblock and the backing.

8. A structure according to claim 7 in whichthe tongues are of a length to support the facing in space'd're'lation to the backing.

9. A. furnace arch including upper and lower courses, the uppercourse comprising blocks rabbeted at their lower edges and arranged in rows and other blocks being rabbeted at their edges, the rabbets being undercut, said other blocks being arranged inrows alternating with the first named rows, the rabbets of the blocks in the several rows being in alignment transversely of the rows and forming channels presenting spaced undercut portions, said aforementioned lower course comprising .blocks having supporting engagement in the undercut rabbets or channel portions and separable from the upper course by movement from the undercut rabbets into the intervening rabbets.

10. A furnace arch including upper and lower courses, the upper course comprising blocks rabbeted at their lower edges and arranged in rows and other blocks rabbeted at thei-redges, the rabbets being undercut, said other blocks being arranged in rows alternating with the first mentioned rows, the rabbets of the blocks in the several rows being in alignment transversely of the rows and forming'channels presenting spaced undercut portions, said aforementioned lower course comprising spaced blocks having supporting engagement with the undercut rabbets or channel portions and separable from the upper course by movement from the un-- dercut rabbets into the intervening rabbets, and additional blocks supported by said spaced blocks.

11. In a furnace structure, a combustion chamber having a top wall, a protecting wall extending in spaced parallel relationto the inner face of said top wall and consisting of a plurality of refractory blocks disposed in a common plane in parallel relation with the inner face of said top wall, and means for suspending the blocks of said protecting wall from said top wall to permit of the removal or insertion of a single block of said protecting wall without disturbing the positions of the other blocks with respect to each other, or with relation to said top wall.

12. In a furnace structure, a combustion chamber having a top wall ofrefractory material, a subjacent refractory protecting wall for said top wall extending in spaced parallel relation to the inner face of the latter to provide an air chamber therebetween and I said air chamber at opposite edges of said 7 protecting Wall having unobstructed communication with the combustion chamber across the entire width of said top wall, and means for supplying air through said-top wall to the space between the same and said protecting wall.-

13. In a furnace structure, a combustion chamber having atop wall composed of rows 'a protecting wall suspended from said top wall in spaced relation thereto and including hanger blocks, certain blocks in alternate rows of the top wall having means for the removable connection of the hanger blocks therewith and the corresponding blocks in intervening rows being of refractory blocks,

constructed to permit of the movement ofthe individual hanger blocks in a direction 'at right angles to the plane of the top wall to a position for connection with or disconnection from the first named blocks of said top wall.

, pended from said top wall in 14:. In a furnace structure, a combustion chamber havinga top wall composed of rows of refractory blocks, a protecting wall susspaced relation thereto and including hanger blocks in alternate rows of the top wall hav-. ing means for the removabletconnection of the hanger blocks therewith and the corresponding blocks in intervening rows being constructed to permit of the movement'of the individual hanger blocks in a direction at right angles to the plane of the top wall to a position for connection with or disconnection from the first named'blocks of said top wall, and said protecting wall also including addiv tional blocks removably supported by and between said hanger blocks and spacing the latter from each other and .retainin the v hanger blocks in connected relation wit the top Wall. o

15. The method of promoting fuel combust on in furnaces which consists in'supplying air to the underside of the top wall of the combustion chamber ,of the furnace, confining such air incontact with the wall surface substantially throughout the area thereof for circulation in Contact with said wall surface whereby ing said confined preheated air to the furnace combustionchamber at one side thereof for mixture with the fuel gases to facilitate ignition of the latter. I

16. The method of promoting. fuel cambustion in furnaces which consists in suppl atmospheric air by the natural draft 0 the furnace to the under side of the top wall of the furnace combustion chamber in substantially uniform distribution throughout the area thereof, confining such induced air in the form of a comparatively thin layer against the under surfaceof said top wall.

while permitting of its free circulation in contact therewith whereby the air is heated, and continuously drawing said confined heat.- ed air by draft tion chamber at one side thereof in the form of a downwardly directed curtain of air extending entirely across said side of the combustion chamber for mixturewith the fuel gases to facilitate ignition thereof,

In testimony that I claim the foregoing as my invention, I have signed my name hereto.

' o JOHN W. GATES.

blocks, certain said air is heated, and supplyinduction into the combus- 

